<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>边框border设置</title>

    <style>
        div{
            width: 300px;
            height: 300px;
            background: pink;
            border-bottom: 10px dashed blue;

            border-style: dashed;
        }

    </style>

</head>
<body>
    <div>
        盒子的颜色
    </div>
</body>
</html>